Electrical burglar-alarm.



F. E..CRAWFORD.

' ELECTRICAL BURGLAR ALARM.

A 'Fu'cATlpN FILED 0m. 7. 1901.

1,174,125. Patented 1M7, 1916.

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f/ fw a) 4 8? iv; 3 Q 1/ n //,".9/n1' F. E. CRAWFORD.

ELECTRICAL BURGLAR ALARM.

APPLICATION FILED opTJ, 1901.

1,174,125. Patented Mar. 7,1916.

ii?! IQ UNITED STATES PATENT @FFIGE.

FRANK E. CRAWFORD, OF IBGSTON, MASSACHUSETTS, ASSIGNGR T0 BANKERSELECTRIC PROTECTIVE ASSOCIATION, OF BOSTON, MASSACHUSETTS, ACGRPOB-ATION OE MAS- SACHUSETTS.

ELECTRICAL BURGLAR-ALARM.

Application filed October 7, 1907.

To all whom it may concern: I

Be it known that I, FRANK E. CRAWFORD, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Electrical Burglar-Alarms, of which the following is aspecification.

My invention relates to new and useful improvements in electricalburglar alarms for guarding and protecting a vault or the like, and itsobject is to pro 'ide a system having means adapted to be operatedmanually from the outside of an electrically guarded structure by theholder of the combination or the key and permit the opening of the doorof the vault without sounding the alarm. In case the door is tamperedwith or opened without authority, an alarm will be sounded.

In the present application, I have shown my invention applied to acombination lock and time lock and when the lock is shot forward and thetime lock set for a predetermined period there is a closed main circuitmaintained through the door of the vault and through the electricallyguarded structure; at the same time, an automatic switch controlling ashunt circuit is opened and held open while the lock maintains a lockedposition. When the predetermined time has elapsed, the party having thecombination can operate same and withdraw the lock. Simultaneously withthe withdrawing of the lock, the automatic switch controlling the shuntcircuit is closed maintaining a circuit through both the main and shuntcircuits, until the door has been opened, when the main circuit isbroken and the shunt circuit remaining closed prevents the sounding'ofthe alarm. That is, only the person or persons having the combinationcan open the door after the predetermined time has elapsed. Thecombination lock and time lock are located within the guarded structureas shown in Figure l so that no access to the timing mechanism can behad without breaking the circuit and sounding the alarm. Means are alsoprovided for pre venting the locking of the safe without setting thetime lock, thereby protecting the safe at any time when in use.

In the accompanying drawings which illustrate a construction embodyingmy invention, Fig. 1 is a perspective view with part of the casingremoved showing the com- Specification of Letters Patent.

.Tatented; Mar. 7, 1916. Serial No. 396,137.

bination lock and the time lock with the bolt withdrawn. Fig. 2 is asimilar view with the bolt thrown forward and the time lock set for apredetermined period. Fig. 3 is a view similar to Fig. 1 with the timelock released and the bolt shot forward previous to opening the door.Fig. 4 is a diagrammatic view illustrating a safe and the electricalstructure around the safe guarding it. Fig. 5 is a diagrammatic viewillustrating the circuits.

Like letters of reference refer throughout the several views.

Referring to Figs. 4 and 5, the system comprises a guarded structure Twhich may be a compartment, vault or cabinet inclosing a safe Y, and Zrepresents the door thereof and adapted to be manually operated by thekey or combination G, which combination may be controlled by a time lockor chronometer N located within the casing A within the guardedstructure T (see Figs. 1, 2 and 3).

The conductors 1, 2, 3, and at and door Z indicate a closed main circuitthrough the battery X inclosing and guarding the struc ture T when thedoor Z is closed.

1, 5 and 6, switch 0, 7, 2, 3 and a represent a shunt circuit normallyopen when the door Z is locked, and which circuit is adapted to beclosed, comprising the main circuit when the door Z is unlocked topermit the opening of said door without sounding an alarm.

3 represents a balance relay which may be located at headquarterscontrolling the alarm circuit 81O through the battery X and alarm Z foroperating said alarm when any of the circuits through the guardedstructure are broken.

A represents a casing located within the door Z and which contains anumber of tumblers B on the shaft C forming a combination lock. Fast onthe shaft 0 is a cam provided with three pawls G, G G and cooperatingwith said cam D is a lock-operating lever E provided with latches F andG which are adapted to be engaged by said pawls G G, G during thedifferent operations or the locking mechanism. Cooperating with saidcombination lock and located within the casing A is the time lock N ofusual construction and adapted by means of the square shaft M to be setfor a predeter mined period in the usual manner.

to like parts J is a latch lever projecting through a slot J andcarrying a latch K on its lower end adapted to cooperate with a pin Kwhen the time lock is set. This lever J has a cross arm K pivoted toarms K and K which arms are pivoted at their lower ends to casing A. Aspring M is provided secured to the lever J to hold latch K incooperation with pin K when the time lock is in operation.

K is a latch pivoted at L to an arm L projecting from the lever J and isnormally held in a vertical position in relation to the said arm by aspring L and a stop L.

Assuming the door Z of the vault open with the combination in theposition shown in Fig. 1 with the time lock N at Zero, the main circuitmaintained through the automatic switch 0 and wires 5, 6 and 7, theoperator to lock the vault,closes the door Z and setting the time lock Nfor a predetermined period, causes the lever J to be thrown over withinthe slot J, moving the stop K from above the lock-operating lever E,permitting the lock H to be shot forward; the handle C- is now turned,causing the pawls G and G to engage with the latches G and F, shootingthe bolt forward, at the same time raising the lever E upward until thepin K is engaged by the latch K (see Fig. 2). In the meantime, theclosing of the door Z has closed the circuit through said door by reasonof said door engaging suitable contacts in the main circuit heretoforedescribed and the shooting forward of bolt H has operated the switch 0,separating the contacts P and P and breaking the circuit through theshunt, thereby preventing an alarm from being sounded. The vault is nowprotected and inaccessible without the sounding of an alarm until thepredetermined time has elapsed, when the lever J is automatically thrownback in the slot J, withdrawing the latch K from engagement with the pinK (see Fig. 2) when the bolt H may be withdrawn by properly operatingthe combination. WVhen the operator is ready to open the vault, thecombination is operated and the lever E falls, the latches F and Gengaging with pawls G and G and the bolt H is withdrawn; simultaneouslywith the withdrawing of the bolt H, the switch 0 is automaticallyclosed, maintaining a circuit through the shunt, and the door Z may nowbe opened without sounding an alarm. After the bolt H has beenwithdrawn, the

Copies of this stop K assumes a position directly over the lever E,preventing the bolt H from being shot forward until the time lock hasbeen properly set. This is to prevent the possibility of the operatorlocking the door Z without the added protection of the time lock.

Having thus described the nature of my invention and set forth aconstruction embodying the same, what I claim as new and desire tosecure by Letters, Patent of the United States is:

1. The combination with an electrically guarded structure of a dooradapted to permit access thereto, a main circuit surrounding saidstructure and comprising portion of a normally closed alarm circuit,said door comprising a part of said main circuit when closed, a shuntcircuit around said door and adapted to maintain the circuit throughsaid alarm when said door is open, means located within said structureadapted to be manually operated from outside said structure to establisha circuit through said shunt to permit the opening of said door withoutsounding the alarm, and time controlled means located within saidstructure co-acting with said manually operated means to prevent theoperation of said manually operated means within a predetermined time.

2. The combination with an electrically guarded structure, of a dooradapted to permit access thereto, a main circuit surrounding saidstructure, and comprising a portion of a normally closed alarm circuit,said door comprising a part of said main circuit when closed, a secondcircuit around said door and adapted to be actuated to maintain thecircuit through said alarm when said door is open, means guarded by themain circuit and adapted to be manually operated from outside saidstructure, to establish a circuit 1.

around the door to permit the opening of L said door without sounding analarm, and

time controlled means guarded by the main circuit and co-acting withsaid manually operated means to prevent the operation of said manuallyoperated means within a predetermined time.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses, this twenty-fifth day ofSeptember A. D. 1907.

FRANK E. CRAWFORD. lVitnesses:

A. L. HURD, L. G. BARTLETT.

patent may be obtained for five cents each, by addressing the.Commissioner of Patents,

Washington, D. C.

